Please also keep in mind the sequence and dependencies around the upgrade, its important in which sequence you upgrade your system. Wolfgang mentioned the correct order already.

NOTE here, this is valid for the manual update, describing Zero Downtime Update (ZDU) would "blast" the topic here, so please find the prerequisites for ZDU in our documentation.

First of all upgrading the utilities (because you need to load initialdata with the recent version)then you have to load the initialdata and update the AE binaries, therefore the system has to be switched off.

After this, you can upgrade AWI or the Java UserInterface. (if the version jump is not too large and does not go over major or minor releases (like upgrading from 12.0.1 to 12.0.4) the UserInterface (AWI) is still compatible also in the older version, but it is advisable to upgrade it short-term after you upgraded the Automation Engine since there can be minor incompatibilities. If you upgrade e.g. from Version 11.2 to 12.0, this would be a major step, in that case you have to upgrade the UserInterface or AWI while upgrading the Automation Engine.